The magnetic susceptibility of a terrestrial, synthetic and lunar ilmenite specimen has been measured from 4 to 300 K. All specimens had a single Ne??el temperature transition which ranged from 56 to 57.7 K. In one case the powdered specimen was partially aligned in the magnetic field prior to the susceptibility measurements and the Ne??el transition was observed to shift to 60 K indicating magnetic anisotropy. A study of several magnetic parameters calculated from the experimental data showed gross impurities in the terrestrial specimen, single-domain to multi-domain metallic iron in the synthetic specimen, and a small amount of superparamagnetic metallic iron in the lunar sample. No multidomain iron was observed in the lunar ilmenite. The results of electron spin resonance measurements were also in general agreement with these findings. Because of the absence of Fe3+ compared to most terrestrial samples it is suggested that the anisotropic magnetic parameters be determined on lunar ilmenite when a large enough single crystal becomes available. ?? 1975.
Additional Publication Details
The Ne??el transition and magnetic properties of terrestrial, synthetic, and lunar ilmenites